Hernia mesh tacks

ABSTRACT

There are disclosed various embodiments of surgical tacks for use in surgical procedures. The tacks generally include a head and a barrel portion extending distally from the head. Preferably, the head and the barrel portion define a throughbore for receipt of a drive instrument. A thread on the head is provided to engage threads in the installation tool. A tissue thread is provided on the barrel portion to engage tissue. Distal and proximal surfaces of the tissue thread may be oriented at various angles relative to the barrel portion. There is also disclosed an insertion instrument to insert one or more tacks as well as a method of use. There is further disclosed a model device for use in explaining the operation of the instrument.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.13/744,699, filed Jan. 18, 2013, which is a continuation of U.S. patentapplication Ser. No. 12/818,541, filed Jun. 18, 2010, now U.S. Pat. No.8,382,778, which is a continuation of U.S. patent application Ser. No.10/517,402, filed on Dec. 7, 2004, now U.S. Pat. No. 7,867,252, which isa U.S. National Stage Application filed under 35 U.S.C. §371(a) ofInternational Application Ser. No. PCT/US2003/018739, filed on Jun. 11,2003, which claims the benefit of and priority to U.S. ProvisionalPatent Application Ser. No. 60/388,119 filed Jun. 11, 2002, the entirecontents of each of these prior applications being incorporated byreference herein.

BACKGROUND

1. Technical Field

The technical field relates to surgical tacks for use in securing meshduring a hernia repair procedure and, more particularly, to absorbablesurgical tacks and insertion instruments.

2. Background of Related Art

During hernia repair surgery, it is often necessary to affix a sectionof mesh over the herniated tissue. This is often accomplished throughthe use of staples or sutures or other affixation type means.

One method of affixing mesh to tissue is through the use of surgicalscrews or tacks. However, known tacks may have a traumatic distal endwhich causes damage to the hernia mesh and unnecessarily injures thetissue as the tack is being inserted. Furthermore, many of these tacksare not configured to be removed after they have been implanted in thepatient. Thus, it would be desirable to provide an absorbable herniatack capable of a traumatic insertion through mesh and into tissue andhaving sufficient tissue surface bearing area to solidly retain the meshagainst the tissue.

It would also be desirable to have a hernia tack which is capable ofbeing removed by means of the insertion tool.

SUMMARY

There are disclosed absorbable hernia tacks suitable for use in securinghernia mesh against tissue. The tacks generally include a barrel portionhaving a head extending distally therefrom. The barrel portion and thehead define a throughbore for receipt of a drive rod of an insertioninstrument so that the hernia tack can be driven through mesh and intotissue. The throughbore may have various non-circular shapes, such asD-shaped, rectangular, polygonal, etc., to increase the drive surfacearea and facilitate insertion in tough tissue. A tissue thread is formedon the barrel portion and is configured to engage tissue as the tack isrotated into the tissue. The tissue thread includes a leading edge atthe distal end of the barrel portion and a trailing edge at a proximalend of the barrel portion. The leading edge has the advantage offollowing a tip of an insertion tool to allow a traumatic entry of thetack into tissue.

The head is provided with a drive thread which is configured to engagean inner surface of an insertion tool and allow the tack to be moveddistally within the insertion tool as the drive rod is rotated. Thedrive thread has a leading edge at its distal end and a trailing edge atits proximal end. Preferably, these surfaces are chamfered or roundedoff so as to facilitate engagement with the insertion tool. Thethroughbore of the hernia tack can have various configurations to matewith a drive rod of an insertion tool. In one embodiment, thethroughbore of the hernia tack has essentially a D-shaped crosssectional area. However, other cross sectional areas may be provided forexample, a rectangular cross section or polygonal cross section.

In various embodiments of the surgical tacks, the proximal and distalsurfaces of the tissue thread may form various acute or obtuse anglesrelative to the barrel portion. These angles provide the advantages ofincreasing the hold of the thread in tissue and allowing for easierinsertion and/or removal of the tack from tissue. Alternatively, one ormore of these surfaces may be perpendicular to the barrel portion. Itshould be noted that the drive thread has a substantially greaterdiameter than the tissue thread to allow the head to seat against themesh without entering the hole in the mesh formed by the barrel andtissue thread. The drive thread and the tissue thread are not connectedthat is, i.e., are discontinuous with respect to each other to achievethis advantage.

There is also disclosed an insertion tool for inserting one or morehernia tacks through mesh and into tissue. The insertion tool generallyincludes an elongated outer tube which is affixed at its distal end to ahandle mechanism. The insertion tool also includes an inner drive rodwhich is rotatably connected to the handle mechanism. A pointed tip ofthe drive rod forms an atraumatic transition with the atraumatic tip ofthe barrel portion to prevent tearing mesh and tissue as the tack isinserted therethrough. Various known handle mechanisms may be utilizedto rotate the inner drive rod with respect to the stationary outer tube.An inner thread may be provided within the outer tube so as to engagethe drive thread of the head of the hernia tack. Preferably, the distalend of the inner thread is flush with the distal end of the outer tubeso that in the event a tack need be removed, the insertion tool may bepositioned over the drive cap of the tack and rotated in an oppositedirection to draw the tack back into the insertion tool and therebyremove the tack from the body.

The inner thread may be provided only at a distal end of the outer tubeor may be provided throughout the entire length of the outer tube. Whenthe drive thread is provided throughout the entire length of the drivetube no biasing spring need be necessary to force additional tacksdistally as they are moved distally along the thread as the drive rod isrotated. However, in the event the inner thread is only provided at thedistal end, various other known means may be utilized to bias subsequenttacks distally towards the inner thread.

There is also disclosed a display model of any insertion tool and herniatack which may be utilized for instructional purposes to demonstrate tosurgeons how the hernia tack and insertion tools work. This is necessarydue to the extremely small nature of the tacks which are generally onthe order of only a few millimeters in diameter. The display modelincludes a mock outer tube having an inner thread along with a drive rodhaving an end cap. A sample hernia tack is also provided. The outer tubeand head cap/drive rod are separable to drop the tack into the proximalend of the model. Thereafter the D-shaped drive rod is positioned withinthe D-shaped throughbore of the tack and the head cap rotated to rotatethe tack out the distal end of the outer tube.

BRIEF DESCRIPTION OF THE DRAWINGS

Various embodiments are described herein with reference to the drawingswherein:

FIG. 1 is a perspective view of a first embodiment of a hernia repairtack;

FIG. 2 is a side view of the hernia repair tack;

FIG. 3 is a side sectional view taken along the line 3-3 of FIG. 2;

FIG. 4 is a proximal end view of the tack;

FIG. 5 is a distal end view of the tack;

FIG. 6 is a perspective view of the tack, similar to that of FIG. 2,with the tack rotated 180;

FIG. 7 is a side view of the tack;

FIG. 8 is a perspective view of the tack illustrating the through bore;

FIG. 9 is a side view of the tack similar to FIG. 7, rotated 180;

FIG. 10 is a perspective view of a tack illustrating an alternatethrough bore;

FIG. 11 is an end view of the tack of FIG. 10;

FIG. 12 is an end view of a tack having a further alternate throughbore;

FIG. 13 is a perspective view of an alternate embodiment of a tack;

FIG. 14 is a perspective view of a further alternate embodiment of atack;

FIG. 15 is a side view of a single tack drive rod;

FIG. 16 is an end view of the rod of FIG. 15;

FIG. 17 is an enlarged side view of the distal end of the rod of FIG.15;

FIG. 18 is a side view of a multi-tack drive rod;

FIG. 19 is an end view of the rod of FIG. 18;

FIG. 20 is an enlarged side view of the distal end of the rod of FIG.18;

FIG. 21 is a perspective view of the rod of FIG. 18 with multiple tacks;

FIG. 22 is a side view, shown in section, of a multi-tack insertiontool;

FIG. 23 is a perspective view of an insertion instrument installing tackin mesh and tissue; and

FIG. 24 is a perspective view, with parts shown in phantom, of a displaymodel of a tack and insertion tool.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Referring to FIGS. 1 and 2, there is disclosed a hernia tack suitablefor atraumatic insertion through hernia mesh and into human tissue.Hernia tack 10 generally includes an elongated barrel portion 12 havinga cap or head 14 at a proximal end 16 of barrel portion 12. Barrelportion 12 extends distally from head 14 and is preferably tapered. Adetent may be formed in a proximal surface 15 of head 14 for receipt ofdriving instrumentation. Preferably, barrel portion 12 and head cap 14define a throughbore 18 therethrough. Throughbore 18 extends from aproximal end 20 of head cap 14 to a distal end 22 of barrel portion 12.

Preferably, distal end 22 is smooth or rounded off to avoid traumatizingtissue and damaging the mesh as tack 10 is installed. Distal end 22forms an atraumatic transition with the tip of a drive rod to preventtearing of mesh and tissue during insertion. Tack 10 can be formed ofany biocompatible material and preferably of a material that isabsorbable. In order to facilitate insertion and retention of herniatack 10 in tissue, barrel portion 12 is provided with a tissue thread 24having a leading edge 26 at a distal end 28 of tissue thread 24 and atrailing edge 30 at a proximal end 32 of tissue thread 24. The use of atissue thread in a hernia mesh tack allows for a larger surface bearingarea against tissue to prevent pulling out of tissue. This is a clearadvantage over prior art types of tacks. Leading edge 26 of tissuethread 24 tapers toward distal end 22 of barrel portion 12 to facilitaterotating tack 10 through hernia mesh and a tissue puncture made with adrive instrument discussed as discussed more fully hereinbelow.

In order to utilize hernia tack 10 with a suitable drive instrument,head 14 is provided with a drive thread 34. Drive thread 34 has aleading edge 36 at a distal end 38 of drive thread 34 and a trailingedge 40 at a proximal end 42 of drive thread 34. The maximum diameter ofdrive thread 34 is greater than the maximum diameter of tissue thread 24so that as tack 10 is rotated through a drive instrument tissue thread24 does not contact the drive instrument and thread 24 is not damaged.

Referring to FIGS. 4 and 5, a drive instrument, described hereinbelow,is configured to pass a drive rod into the detent in head 14 or throughthroughbore 18 and rotate tack 10. As shown, throughbore 18 has anarcuate portion 44 and a flat portion 46 which combine to form agenerally D-shaped throughbore. This allows a similarly shaped drive rodto engage inner surface of throughbore 18 and rotate tack 10.

Tissue thread 24 has a proximal surface 48 which is orientedapproximately perpendicularly or at a 90° angle to barrel portion 12.This provides a generally flat surface area to engage tissue to avoidpulling out of tack 10 from tissue. Referring for the moment to FIG. 7,a distal face 49 of thread 24 forms and obtuse angle with barrel portion12 to facilitate insertion of tack 10.

As shown in FIG. 3, a proximal end of head 14 has a chamfered surface 50to facilitate receipt of insertion tools, such as a drive rod, inthroughbore 18.

Referring now to FIGS. 6 and 7, drive thread 34 is more clearlyillustrated. As shown, leading edge 36 and trailing edge 40 of drivethread 34 are rounded so as to facilitate ease of insertion in a driveapparatus. Further, trailing edge 40 is flush with a proximal surface 15of head 14 to facilitate reengagement of tack 10 by an insertioninstrument to facilitate removal of tack 10.

Referring to FIGS. 7 and 8, it can be seen that trailing edge 30 oftissue thread 24 and leading edge 36 of drive thread 34 arediscontinuous and do not form one continuous thread. In particular, atapered edge 37 of drive thread 34 prevents drive thread 34 fromcontinuing into tissue after trailing edge 30 of tissue thread 24 isfully inserted in the tissue. FIG. 8 also shows the D-shaped throughbore18.

FIG. 9 illustrates the generally flat proximal surface 48 of tissuethread 24 as well as the transition zone 51 between tissue thread 24 anddrive thread 34.

Referring now to FIGS. 10 and 11 there is illustrated an alternativeembodiment of a hernia tack 52 which in most respects is the same ashernia tack 10. However, hernia tack 52 includes a square shapedthroughbore 54 for engagement with a different style drive apparatus.The square shape of throughbore 54 provides more surface area for theinsertion tool to engage. This may aid in driving tack 52 into toughtissues without possibility of stripping throughbore 54.

Similarly, referring now to FIG. 12, there is illustrated an end view ofan alternative tack 56 which has a polygonal shaped throughbore 58 toprovide yet more surface area for engagement with insertioninstrumentation. Various other throughbore shapes, such as, for example,oval, star shaped, etc. may be provided to operate with variousinsertion instruments. Any non-circular shape for the cross section ofthe throughbore is contemplated herein.

Referring now to FIG. 13, there is disclosed an alternative embodimentof a surgical tack having a differing style tissue thread. Tack 60generally includes a barrel portion 62 and a head 64. Head 64 has adrive thread 65 to engage threads in an insertion tool. In thisembodiment of tack 60, a proximal surface 68 of a tissue thread 66generally forms an obtuse angle with respect to barrel portion 62. Thisangle of tissue thread 66 may assist in those situations where tack 60needs to be removed or backed out of the tissue and the mesh. A distalsurface 69 of thread 66 may be oriented substantially perpendicular tobarrel portion 62 as shown. While not specifically shown, either or bothof proximal surface 68 and distal surface 69 of tissue thread 66 mayform an angle of less than 90 degrees with barrel portion 62 to aid inanchoring tack 60 within tissue.

Referring now to FIG. 14, there is disclosed a further alternativeembodiment of a surgical tack. Tack 70 is similar to tacks 10 and 60hereinabove and generally includes a barrel portion 72 having a head 74.Head 74 has a drive thread 75 to engage the threads in an insertioninstrument. Tissue thread 76 formed on body portion 72 includes a distalsurface 78 which forms an obtuse angle with barrel portion 72. This mayassist in driving tack 70 through the mesh and into the tissue. Asshown, a proximal surface 79 of tissue thread 76 may be orientedperpendicular to barrel portion 72.

Referring now to FIG. 15 there is illustrated a drive rod 80 for use ina tack applying instrument. Drive rod 84 is utilized in those insertiontools which are configured to apply a single tack to hernia mesh andtissue. Drive rod 80 generally includes a proximal end section 82configured to be engaged by an actuation mechanism of a surgicalinstrument such that actuation of the instrument rotates drive rod 80.Drive rod 80 also includes a center section 84 extending distally fromproximal end section 82 and a distal section 86 extending distally fromcenter section 84. Preferably, distal section 86 terminates in a sharptissue penetrating tip 88.

As best shown in FIGS. 16 and 17, distal section 86 of drive rod 80includes a flat portion 90 and an arcuate portion 92 which forms agenerally D-shape so as to engage the generally D-shaped throughbore ofa tack. As best shown in FIG. 18, an abutment surface 94 is formedbetween a distal end 96 of center section 84 and a proximal end 98 ofdistal section 86. This abutment surface 94 is configured to engage theproximal surface of the head of the tack.

Referring now to FIGS. 18-20, and initially with respect to FIG. 18,there is illustrated drive rod 100 for use with multiple tacks. Driverod 100 generally includes a proximal section 102 and a distal section104. An abutment surface 106 is formed between distal section 104 andproximal section 102 to engage a tack. Distal section 104 sufficientlyelongate so as to receive multiple tacks therealong.

Referring to FIG. 19, distal section 104 includes a flat surface 108 andan arcuate surface 110 which is configured to engage the throughbore ofthe prior disclosed hernia tacks. As shown in FIG. 20, distal section104 has a pointed distal end 112.

Referring to FIG. 21, there is illustrated a pair of hernia tacks 60provided on drive rod 100.

Referring now to FIG. 22, the distal end of an insertion tool isdisclosed for providing multiple surgical tacks 60 to hernia mesh andtissue. Insertion tool 120 includes an outer tube 122 having rotatabledrive rod 100 positioned within outer tube 122. As discussedhereinabove, various known handle mechanisms may be provided to rotatedrive rod 100 relative to outer tube 122. One known device is disclosedin U.S. Pat. No. 5,582,616 to Bolduc. Drive rod 100 includes pointeddistal end 112 to facilitate initially piercing tissue and mesh. Asshown, insertion tool 120 includes an inner thread 124 which isconfigured to engage drive thread 65 of head 64 of a tack 60. Innerthread 124 may be integrally formed in outer tube 122. It should benoted that inner thread 124 may extend completely or partially along theinner surface of outer tube 122. If thread 124 is only provided at thedistal end of tube 122, a spring may be used to bias the tacks distallytoward thread 124 in tube 122. A distal end 125 of inner thread 124 ispositioned flush with the distal end of tube 122. This facilitatesreengagement of inner thread 124 with thread 65 of head 64 in the eventthat tack 60 needs to be withdrawn after installation. As clearly shown,when tacks 60 are loaded into insertion tool 120, tissue thread 66 doesnot contact inner thread 124 and is not damaged thereby.

Referring to FIG. 23, in use, insertion tool 120 having a handle 126,elongate tube 122 extending distally from handle 126, and an actuator128 configured to rotate inner rod 100, is positioned such that pointeddistal end 112 is against mesh m and underlying tissue t and coveringthe hernial defect d. Thereafter, a handle mechanism (not shown) may beactuated to rotate drive rod 100 relative to outer tube 212. This causesdrive thread 65 of head cap 64 of tack 60 to engage inner thread 124 anddrive tack 60 through the mesh m and into tissue t. As noted above,tacks 60 may be biased distally by a spring surrounding drive rod 100 ormaybe moved distally by providing inner thread partially, orsubstantially along the entire length of, outer tube 122.

Referring now to FIG. 24 there is disclosed a display model of thehernia tack and an insertion tool which can be used to show how theactual tack, which is very small on the order of a few millimeters indiameter, is driven out of the insertion tool and into mock tissue andmesh. Display model 130 includes an insertion tool 132 and a tack 134.Insertion tool 130 has an outer tube 136 having an inner thread 138. Aswith the insertion tools described hereinabove, thread 138 may beintegrally formed in outer tube 136 or a separate component affixed toan inner surface of outer tube 136. Additionally, while thread 138 iscontemplated as extending completely through outer tube 136, thread 138may only be provided at the distal end of tube 136 and a spring or othermeans (not shown) may be provided to bias tacks distally within outertube 136.

Insertion tool 132 also includes a drive knob 140 having a drive rod 142extending distally therefrom and through inner tube 136. Drive rod 142has a pointed distal end to simulate piercing tissue. Drive rod 142 alsohas arcuate and flat sections configured to engage tack 134 similar todrive rod 100 hereinabove. Tack 134 has a throughbore 144 to receivedrive rod 142.

To demonstrate the use of the tack and applier, tack 134 is placed intube 136 and insertion tool 132 is manipulated to position drive rod 142in a through bore 150 of tack 134. Knob 140 is then rotated to drivetack 134 out of tube 136.

It will be understood that various modifications may be made to theembodiments disclosed herein. For example, as discussed above, otherconfigurations for the throughbore in the tack, as well as variousangles of the tissue threads, may be provided on the tacks. Therefore,the above description should not be construed as limiting, but merely asexemplifications of preferred embodiments. Those skilled in the art willenvision other modifications within the scope and spirit of the claimsappended hereto.

1. (canceled)
 2. A surgical system comprising: a surgical instrumentincluding a rotatable torque transmitting shaft having a non-circular,transverse, cross-sectional profile; and a plurality of surgical tackseach having a length, each tack defining a central passage extendingthrough the entire length thereof, the central passage of each tackhaving a non-circular, transverse, cross-sectional profile, wherein eachtack is slidably and non-rotatably supported on the shaft such that theshaft extends through the central passage of each tack.
 3. The surgicalsystem according to claim 2, wherein rotation of the shaft transmits atorque to each tack.
 4. The surgical system according to claim 2,wherein the non-circular, transverse, cross-sectional profile of theshaft defines at least one outer planar radial surface, wherein the atleast one outer planar radial surface of the shaft rotationally engagesa torque receiving surface defined in the central passage of each tack.5. The surgical system according to claim 4, wherein the non-circular,transverse, cross-sectional profile of the central passage of each tackdefines at least one planar radial passage surface, wherein the at leastone planar radial passage surface of each tack is configured to receivea torque from the shaft.
 6. The surgical system according to claim 5,wherein the non-circular, transverse, cross-sectional profile of thecentral passage of each tack has a hexagonal profile.
 7. The surgicalsystem according to claim 2, wherein the at least one outer planarradial surface of the shaft is in contact with the entire length of eachtack.
 8. The surgical system according to claim 7, wherein a torquetransmitted from the shaft to each tack is transmitted to the entirelength of each tack.
 9. The surgical system according to claim 2, eachtack is formed from a biocompatible, absorbable material.
 10. Thesurgical system according to claim 2, further comprising: an outer tubedisposed about the shaft and the at least one tack; and a threaddisposed within an interior of the outer tube, wherein each tack isoperatively coupled to the internal thread such that rotation of theshaft rotates each tack relative to the outer tube, and wherein theoperative coupling of each tack with the internal thread of the outertube causes each tack to axially translate relative to the shaft. 11.The surgical system according to claim 2, wherein each tack includes acoil surrounding the central passage thereof.
 12. A surgical systemcomprising: a plurality of surgical tacks, each tack including aninterior space having a first non-circular, transverse, cross-sectionalconfiguration, and a coil for facilitating advancement of the tacksthrough tissue upon rotation of the tacks; and a surgical instrument forinsertion of the tacks into tissue, the surgical instrument including ashaft configured for positioning within the interior space of each tacksuch that the tacks are positioned about the shaft, the shaft defining asecond non-circular, transverse, cross sectional configurationcorresponding to the first non-circular, transverse, cross-sectionalconfiguration of the interior space of each tack of each tack such thatrotation of the shaft causes corresponding rotation of the tacks. 13.The surgical system of claim 12, wherein the interior space defined byeach tack is hexagonal in configuration.
 14. The surgical system ofclaim 13, wherein the first, transverse, non-circular cross-sectionalconfiguration of each tack includes a plurality of first contactsurfaces defined by intersecting portions of the tack, and the second,transverse non-circular cross-sectional configuration of the shaftincludes a plurality of second contact surfaces defined by intersectingportions of the shaft.
 15. The surgical system of claim 14, wherein theplurality of first contact surfaces of the tacks are configured anddimensioned for engagement with the second contact surfaces of the shaftupon positioning of the shaft within the interior spaces of the tacks.16. The surgical system of claim 15, wherein each tack is formed from abiocompatible, absorbable material.
 17. A surgical system comprising: asurgical instrument including a shaft with a non-circular exteriorsurface, the exterior surface of the shaft including a plurality oftorque transmitting surfaces defined by intersecting outer planarsurfaces of the shaft; and a plurality of tacks, each tack including acentral passage having a non-circular interior surface corresponding tothe exterior surface of the shaft, the interior surface of each tackincluding a plurality of torque receiving surfaces defined byintersecting inner planar surfaces of the tack, the torque receivingsurfaces of the tacks being engaged by the torque transmitting surfacesof the shaft, as the shaft is rotated, resulting in correspondingrotation of the tacks and advancement of the tacks.
 18. The surgicalsystem of claim 17, wherein each tack includes a coil.
 19. The surgicalsystem of claim 18, wherein the coil of each tack includes a tapereddistal end facilitating advancement of the tacks through the tissue. 20.The surgical system of claim 19, wherein each tack defines an interiorspace configured and dimensioned to receive the shaft.
 21. The surgicalsystem of claim 20, wherein the interior space defined by each tack ishexagonal in configuration.
 22. The surgical system of claim 21, whereineach tack is formed from a biocompatible, absorbable material.
 23. Asurgical system comprising: a surgical instrument including a rotatabletorque transmitting shaft having a non-circular, transverse,cross-sectional profile; and a plurality of surgical tacks, each tackincluding: a distal threaded tissue engaging portion defining a centralnon-circular, transverse cross-sectional passage therethrough, whereinthe central passage of the tissue engaging portion defines a torquereceiving surface; and a proximal mesh engaging portion integrallyformed with the distal threaded tissue engaging portion, wherein themesh engaging portion secures a surgical mesh to tissue, wherein eachtack is slidably and non-rotatably supported on the shaft such that theshaft extends through the central passage of each tack, and whereinrotation of the shaft transmits a torque to each tack.
 24. The surgicalsystem according to claim 23, wherein the non-circular, transverse,cross-sectional profile of the shaft defines at least one outer planarradial surface, wherein the at least one outer planar radial surface ofthe shaft rotationally engages the torque receiving surface defined inthe central passage of each tack.
 25. The surgical system according toclaim 24, wherein the non-circular, transverse, cross-sectional profileof the central passage of each tack defines at least one planar radialpassage surface, wherein the at least one planar radial passage surfaceof each tack is configured to receive the torque from the shaft.
 26. Thesurgical system according to claim 25, wherein the non-circular,transverse, cross-sectional profile of the central passage of each tackhas a hexagonal profile.
 27. The surgical system according to claim 24,wherein the at least one outer planar radial surface of the shaft is incontact with the entire tissue engaging portion of each tack.
 28. Thesurgical system according to claim 27, wherein a torque transmitted fromthe shaft to each tack is transmitted to the entire length of each tack.29. The surgical system according to claim 23, each tack is formed froma biocompatible, absorbable material.
 30. The surgical system accordingto claim 23, further comprising: an outer tube disposed about the shaftand the at least one tack; and a thread disposed within an interior ofthe outer tube, wherein each tack is operatively coupled to the internalthread such that rotation of the shaft rotates each tack relative to theouter tube, and wherein the operative coupling of each tack with theinternal thread of the outer tube causes each tack to axially translaterelative to the shaft.